Which characteristic is influenced by both genetic and environmental factors?

The chosen answer focuses on phenotype, which refers to the observable characteristics or traits of an organism resulting from the interaction of its genetic makeup (genotype) and environmental influences. Phenotypes encompass a wide range of traits, such as physical appearance, behavior, and physiological properties.

Genetic factors contribute to phenotype by providing the hereditary instructions that define traits. However, environmental factors—such as climate, nutrition, exposure to toxins, and social interactions—can also significantly impact the expression of these traits. For instance, two organisms with the same genotype may exhibit different phenotypic traits if they are raised in different environments. This interplay between genotype and environmental influences illustrates the complexity of biological expression and the concept that phenotype is not solely determined by genetics but is a result of both genetic predisposition and environmental context.

In contrast, the other options represent specific aspects of genetics that do not inherently embody the interaction between genetics and the environment. Genotype refers strictly to the genetic constitution of an organism without considering environmental effects. Chromosomal count is a fixed characteristic determined by genetics that does not change with environmental influences. Gene expression, while influenced by environmental factors, is a component of the broader concept of phenotype and does not encompass the observable traits as a whole. Therefore, phenotype is